My Probes Disappear When I Run My VI

Updated Sep 4, 2018

Reported In


  • LabVIEW

Issue Details

When I place a probe on a wire in my VI block diagram, the probe window appears normally and remains the front most window as long as a LabVIEW window is active. However, when I run the VI, the probe window disappears. The probe numbers are still on the block diagram, but the window is not visible. Why is my probe window disappearing?


This behavior is caused by a setting in VI Properties that controls Window Appearance. To access this setting, go to File » VI Properties.  Then, under the Category drop-down menu, select Window Appearance » Customize.... In older versions of LabVIEW, you need to uncheck the property labeled Window is Modal (stays on top). In newer versions of LabVIEW, this property is called Window Behavior and should be set to Default or Floating to keep your probe window visible during VI execution. To learn more about the different Window Behavior settings, please see the links My LabVIEW Debugging Tools Are Not Working and Front Panel Window - LabVIEW help.


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